A riveting die and a riveting method

Abstract

The application discloses a riveting die and a riveting method. The riveting die comprises first, second, third and fourth dies arranged in sequence in corresponding stations. The first die is used for punching mounting grooves on a material belt. The second die is used for bending two end portions of the silver sheet in the width direction. The third die is used for feeding the bent silver sheet into the mounting grooves and punching fixing grooves at two ends of the mounting grooves. The fourth die is used for extruding the two fixing grooves to press the bent portion of the silver sheet against the side surface of the mounting groove. The riveting die and the riveting method can realize riveting of the silver sheet on the material belt during terminal stamping, and can complete the terminal stamping and the silver sheet riveting through only one process, so that the misplacement or the missing of the silver sheet is avoided, the defective rate is reduced, the production efficiency of the terminal is improved, and the labor is saved.

Description

Technical Field

[0001] This invention relates to the field of solder riveting technology on terminals, and more specifically to a riveting mold and a method for riveting using the riveting mold. Background Technology

[0002] With the development and popularization of new energy vehicles, the use of automotive electronic products is becoming increasingly widespread. Automotive electronic products rely heavily on both low-voltage signal transmission and high-voltage current transmission. Consequently, the development of copper terminal embedded plastic injection molding has also been rapid. Utilizing the excellent conductivity of copper terminals and the insulation properties of plastic, along with the possibility of molding complex product designs, the use of embedded injection molded parts in automotive electronic products is increasing. At the same time, the modularity of automotive electronic products is increasing, and the current transmitted after vehicle electrification is also increasing. Vehicles operate in harsh environments such as vibration and high temperatures, raising concerns about the reliability of electrical connections between two modules. Resistance welding is a commonly used connection method to connect the terminals on two modules. To increase reliability, solder (small pieces of silver-containing coil material) is often added between the two welding surfaces to enhance the peel strength between the two welded terminals. Currently, the common practice for attaching solder to terminals is to add an additional process after the terminal stamping production to braze the solder onto the terminal, which is time-consuming and labor-intensive. Summary of the Invention

[0003] In view of this, in order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a riveting mold that can directly rivet solder onto the strip and a riveting method using the riveting mold, so as to solve the problem that in the prior art, an additional process of soldering is required after the terminal is stamped, resulting in low production efficiency and increased labor costs.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] On one hand, the present invention provides a riveting die for directly riveting silver sheets onto a strip during the stamping of terminals on the strip. The riveting die sequentially includes a first die, a second die, a third die, and a fourth die located at corresponding workstations. The first die is used to punch an installation groove on the strip. The second die includes two upper bending parts and a lower bending part, the bottom ends of the two upper bending parts matching the bottom ends of the lower bending parts. The second die is used to bend the two ends of the silver sheet along its width direction. The third die includes a cutting part and first upper die parts located on both sides of the cutting part. The third die is used to feed the bent silver sheet into the installation groove and punch fixing grooves at both ends of the installation groove. The fourth die includes two second upper die parts. The fourth die is used to press the two fixing grooves, so that the fixing grooves press the bent portion of the silver sheet against the side of the installation groove.

[0006] According to some preferred embodiments of the present invention, a first punch portion is provided at the lower end of the first mold. The first punch portion includes a first part and first protrusions located at both ends of the first part. The height of the first part is less than the height of the first protrusions, and the length of the first part is less than the distance between the two first protrusions. A first inclined surface is provided between the side of the first part near the corresponding first protrusion and the side of the first protrusion near the first part. The first punch portion is used to punch the mounting groove on the strip. In some embodiments of the present invention, the strip is made of copper, and the terminal is obtained by stamping on the copper strip. During the terminal stamping process, the first punch portion of the first mold pre-punches a mounting groove of a certain depth and size on the copper strip. The shape and size of the mounting groove are the same as those of the first punch portion.

[0007] According to some preferred embodiments of the present invention, two upper bending members are correspondingly arranged. The lower end of each upper bending member is provided with a second protrusion, the second protrusion including a second inclined surface, and the cross-section of the second protrusion being a right-angled trapezoid. The upper end of each lower bending member is provided with a third protrusion, the third protrusion including two third inclined surfaces, the two third inclined surfaces being respectively close to the two second inclined surfaces. A silver strip is placed between the two upper and lower bending members of the second mold. Through the compression between the upper and lower bending members, both ends of the silver strip are bent along the width direction. The bent portion is located between the second inclined surface of the second protrusion of the upper bending member and the third inclined surface of the third protrusion of the lower bending member. The bent portion can extend into the mounting groove, which helps to increase the fit between the two during riveting.

[0008] According to some preferred embodiments of the present invention, the second inclined surface is parallel to the corresponding third inclined surface, and the distance between the two sides of the two second inclined surfaces near the upper end of the upper bending member is less than the length of the top surface of the third protrusion. The second inclined surface being parallel to the corresponding third inclined surface is to form a complete bent portion. If the second and third inclined surfaces are not parallel, when bending the end of the silver strip, the intersection of the second and third inclined surfaces may cause the bent portion to be crushed or bent again, resulting in a mismatch with the mounting groove and preventing riveting. The distance between the two sides of the two second inclined surfaces near the upper end of the upper bending member is less than the length of the top surface of the third protrusion, allowing the two second protrusions of the upper bending member to limit the bent silver strip, preventing the bent silver strip from sliding directly out of the space above the two second protrusions.

[0009] According to some preferred embodiments of the present invention, the acute angle formed between the first inclined surface and the plane containing the bottom surface of the first protrusion, and the acute angle formed between the second inclined surface and the plane containing the bottom surface of the second protrusion, are both 44.9-45.1°. In some embodiments of the present invention, the acute angle formed between the first inclined surface and the plane containing the bottom surface of the first protrusion, and the acute angle formed between the second inclined surface and the plane containing the bottom surface of the second protrusion, are both 45°. Correspondingly, the inclination angle of the bent portion obtained by bending the silver strip through the second die is also 45°, and the inclination angle of the mounting groove formed on the strip by the first punch is also 45°, so that the two match each other and are easy to rivet.

[0010] According to some preferred embodiments of the present invention, two first upper mold members are correspondingly arranged, and each first upper mold member has a fourth protrusion at its lower end. The cross-section of the fourth protrusion is trapezoidal, and the distance between the two fourth protrusions is greater than the distance between the two first protrusions. The length of the bottom surface of the cutting member is greater than or equal to the distance between the two first protrusions. The cutting member is provided to cut the bent silver strip into a silver sheet whose length and width match the dimensions of the corresponding mounting groove. In addition, a spring is installed at the top of the cutting member. After cutting, the cutting member further presses the silver sheet directly into the mounting groove from directly above it using the pressure of the spring. The two first upper mold members are located on both sides of the cutting member, and the two fourth protrusions are used to punch fixing grooves on both sides of the mounting groove already punched on the strip. In some embodiments of the present invention, the length of the bottom surface of the cutter is greater than the distance between the two first protrusions, that is, the length of the bottom surface of the cutter is greater than the distance between the bent portions at both ends of the silver sheet, so as to ensure that the cutter can fully press the silver sheet into the mounting groove when pressing the cut silver sheet into the mounting groove, and to avoid uneven pressing.

[0011] According to some preferred embodiments of the present invention, the fourth mold includes a press-in component, the length of the bottom surface of which is greater than or equal to the distance between the two first protrusions; two second upper mold components are correspondingly arranged, each of the second upper mold components having a fifth protrusion at its lower end, the distance between the two fifth protrusions being greater than the distance between the two first protrusions. In some embodiments of the present invention, the length of the bottom surface of the press-in component is equal to the distance between the two first protrusions, ensuring that the silver sheet is completely pressed into the mounting groove, further pressing it tightly, and avoiding uneven pressing of the silver sheet, which could lead to unsuccessful riveting. Through the two fifth protrusions of the two second upper mold components, the corresponding fixing groove is pressed, causing the inclined surface of the fixing groove near the mounting groove to tilt towards the bent portion of the silver sheet, and pressing it tightly onto the upper surface of the bent portion, increasing the firmness of the silver sheet riveting.

[0012] According to some preferred embodiments of the present invention, a fifth mold is included, the lower end of which is provided with a second punch portion. The second punch portion includes a second part and sixth protrusions located at both ends of the second part. The height of the second part is greater than the height of the sixth protrusions and greater than the height of the first part. The height of the sixth protrusions is greater than the height of the first protrusions. The length of the second part is less than the distance between the two sixth protrusions. The second punch portion is used to deepen the mounting groove on the strip. In some embodiments of the present invention, a fifth mold is also included. The fifth mold is used after the first mold. After the mounting groove is pre-stamped on the strip using the first mold, the second punch portion of the fifth mold is used to perform fine stamping on the mounting groove to form a deeper groove, avoiding insufficient depth or incomplete formation of the mounting groove shape during the first pre-stamping. A sixth inclined surface is provided between the side of the second part near the corresponding sixth protrusion and the side of the sixth protrusion near the second part; the acute angle formed between the sixth inclined surface and the horizontal plane containing the top surface of the sixth protrusion is also 45°.

[0013] According to some preferred embodiments of the present invention, the fourth protrusion includes a fourth inclined surface, and the fifth protrusion includes a fifth inclined surface, the length of which is greater than the length of the fourth inclined surface. When the fifth protrusion is located in the fixing groove, the length of the fifth inclined surface is greater than the distance between the end of the fifth inclined surface away from the mounting groove and the end of the corresponding bent portion of the silver sheet away from the fixing groove. The length and position of the fifth inclined surface are set to ensure that when the fifth inclined surface is pressed against the bent portion of the silver sheet, it can completely press against the upper surface of the bent portion, ensuring the firmness of the silver sheet riveting in the deepening groove and preventing the silver sheet from falling off. In some embodiments of the present invention, the acute angle formed between the fourth inclined surface and the horizontal plane is 50.1-50.3°, preferably 50.2°; the acute angle formed between the fifth inclined surface and the horizontal plane is 42.9-43.1°, preferably 43°.

[0014] On the other hand, the present invention also provides a riveting method for riveting silver sheets onto copper strips using the riveting mold described above, comprising the following steps: punching an installation groove on the strip using a first mold; bending both ends of the silver strip using a second mold; cutting the bent silver strip into a silver sheet using a third mold and pressing it into the installation groove; punching a fixing groove on the strip; and finally pressing the silver sheet into the installation groove using a fourth mold, and pressing the fifth inclined surface of the fixing groove onto the bent portions at both ends of the silver sheet to complete the riveting of the silver sheet. In some embodiments of the present invention, between the two steps of punching an installation groove on the strip using a first mold and bending both ends of the silver strip using a second mold, a step of further punching a deeper groove using a fifth mold on the basis of the installation groove is included. This step helps to ensure the accuracy of the depth and size of the groove for riveting the silver sheet, better matches the shape of the silver sheet, and facilitates riveting.

[0015] Compared with the prior art, the advantages of this invention are as follows: The riveting mold of the present invention, by setting corresponding first mold, second mold, third mold and fourth mold at different work stations, realizes the direct riveting of silver sheets on the material strip during the terminal stamping process. The terminal stamping and silver sheet riveting can be completed in only one process, avoiding misplacement or omission of silver sheets, reducing the defect rate, improving the production efficiency of terminals and saving labor. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a cross-sectional view of the first mold in a preferred embodiment of the present invention;

[0018] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0019] Figure 3 This is a cross-sectional view of the second mold in a preferred embodiment of the present invention;

[0020] Figure 4 for Figure 3 Enlarged view of point B in the middle;

[0021] Figure 5 This is a cross-sectional view of the third mold in a preferred embodiment of the present invention;

[0022] Figure 6 for Figure 5 Enlarged view of point C in the middle;

[0023] Figure 7 This is a cross-sectional view of the fourth mold in a preferred embodiment of the present invention;

[0024] Figure 8 for Figure 7 Enlarged view at point D;

[0025] Figure 9 This is a cross-sectional view of the fifth mold in a preferred embodiment of the present invention;

[0026] Figure 10 for Figure 9 Enlarged view at point E in the middle;

[0027] Figure 11 This is a cross-sectional view of the conveyor belt after the mounting groove has been punched in a preferred embodiment of the present invention;

[0028] Figure 12 In order to be in Figure 11 A cross-sectional view of the strip after the deep groove is punched on the material strip;

[0029] Figure 13 In order to be in Figure 12 A cross-sectional view of the strip after the fixing groove is punched on it;

[0030] In the attached diagram: First mold-1, First punching part-11, First part-111, First protrusion-112, First inclined surface-113, Second mold-2, Upper bending part-21, Second protrusion-211, Second inclined surface-212, Lower bending part-22, Third protrusion-221, Third inclined surface-222, Third mold-3, Cutting part-31, First upper mold part-32, Fourth protrusion-321, Fourth inclined surface-322, Platform-33, Fourth mold-4, Press-in part-41, Second upper mold part-42, Fifth protrusion-421, Fifth inclined surface-422, Fifth mold-5, Second punching part-51, Second part-511, Sixth protrusion-512, Sixth inclined surface-513, Silver sheet-6, Material strip-7, Mounting groove-8, Deepening groove-9, Fixing groove-10. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0032] Example 1

[0033] This embodiment provides a riveting die for directly riveting silver sheets onto copper strips during terminal stamping. Please refer to [link to relevant documentation]. Figure 1-10 The riveting mold in this embodiment includes a first mold 1, a second mold 2, a third mold 3, a fourth mold 4, and a fifth mold 5, each located at a corresponding workstation. The first mold 1 is used to punch an mounting groove 8 on the strip 7; the second mold 2 is used to bend the two ends of the silver sheet 6 along its width; the fifth mold 5 is used to further punch a deeper groove 9 based on the mounting groove 8; the third mold 3 is used to feed the bent silver sheet 6 into the mounting groove 8 and punch fixing grooves 10 at both ends of the mounting groove 8; the fourth mold 4 is used to press the two fixing grooves 10 so that the fixing grooves 10 press against the upper surface of the bent part of the silver sheet 6 near the side of the mounting groove 8. The strip 7 in this embodiment is made of copper, and copper terminals can be obtained by stamping the copper strip 7.

[0034] like Figure 1-2 As shown in Figure 11, a first punching part 11 is provided at the lower end of the first mold 1. The first punching part 11 includes a first part 111 and first protrusions 112 located at both ends of the first part 111. The first punching part 11 is used to pre-punch the copper strip 7 to obtain the mounting groove 8, which matches the first punching part 11. The height of the first protrusion 112 is 0.35mm, the height of the first part 111 is less than the height of the first protrusion 112, and the length of the first part 111 is less than the distance between the two first protrusions 112. A first inclined surface 113 is provided between the side of the first part 111 near the corresponding first protrusion 112 and the side of the first protrusion 112 near the first part 111. The acute angle formed between the first inclined surface 113 and the plane containing the bottom surface of the first protrusion 112 is 45°.

[0035] like Figure 3-4 As shown in Figure 12, the lower end of the fifth mold 5 is provided with a second punch part 51, which includes a second part 511 and sixth protrusions 512 located at both ends of the second part 511. The second punch part 51 performs precision stamping on the mounting groove 8 to obtain a deepened groove 9, which matches the second punch part 51. The height of the sixth protrusion 512 is 0.355mm. The height of the second part 511 is greater than the height of the sixth protrusion 512 and greater than the height of the first part 111. The height of the sixth protrusion 512 is greater than the height of the first protrusion 112. The length of the second part 511 is less than the distance between the two sixth protrusions 512. A sixth inclined surface 513 is provided between the side of the second part 511 near the corresponding sixth protrusion 512 and the side of the sixth protrusion 512 near the second part 511. The acute angle formed between the sixth inclined surface 513 and the horizontal plane containing the top surface of the sixth protrusion 512 is also 45°.

[0036] like Figure 5-6As shown, the second mold 2 includes two corresponding upper bending parts 21 and lower bending parts 22, with the bottom ends of the two upper bending parts 21 matching the bottom ends of the lower bending parts 22. A second protrusion 211 is provided at the lower end of the upper bending part 21, the cross-section of which is a right-angled trapezoid, and the second protrusion 211 includes a second inclined surface 212. A third protrusion 221 is provided at the upper end of the lower bending part 22, the third protrusion 221 including two third inclined surfaces 222, the two third inclined surfaces 222 being close to the two corresponding second inclined surfaces 212, the second inclined surfaces 212 being parallel to the corresponding third inclined surfaces 222, and the distance between the two sides of the two second inclined surfaces 212 near the upper end of the upper bending part 21 being less than the length of the top surface of the third protrusion 221. The acute angle formed between the second inclined surface 212 and the plane containing the bottom surface of the second protrusion 211 is 45°. The silver strip is bent at both ends along the width direction by the mutual compression between the two second protrusions 211 and the third protrusion 221.

[0037] like Figure 7-8 As shown in Figure 13, the third mold 3 includes a cutting component 31, a first upper mold component 32 located on both sides of the cutting component 31, and a platform 33 for placing the silver strip. A spring is provided at the end of the cutting component 31 away from the silver strip. The cutting component 31 is used to cut the bent silver strip to form a silver sheet 6 whose length and width match the dimensions of the deepening groove 9. After cutting, the cutting component 31 further presses the silver sheet 6 directly into the mounting groove 8 from directly above it using the pressure of the spring. Two first upper mold parts 32 are correspondingly arranged, and each first upper mold part 32 has a fourth protrusion 321 at its lower end. The cross-section of the fourth protrusion 321 is trapezoidal. The fourth protrusion 321 includes a fourth inclined surface 322. The acute angle formed between the fourth inclined surface 322 and the horizontal plane is 50.2°. The height of the fourth protrusion 321 is 0.301mm. The length of the bottom surface of the cutting part 31 is greater than the distance between the two first protrusions 112, that is, the length of the bottom surface of the cutting part 31 is greater than the distance between the two bent parts at both ends of the silver sheet 6, so as to ensure that when the cutting part 31 presses the cut silver sheet 6 flat into the mounting groove 8.

[0038] like Figure 9-10As shown, the fourth mold 4 includes a press-in part 41 and corresponding second upper mold parts 42 located on both sides of the press-in part 41. Each second upper mold part 42 has a fifth protrusion 421 at its lower end. The height of the fifth protrusion 421 is 0.309 mm, and the distance between two fifth protrusions 421 is greater than the distance between two first protrusions 112, meaning the mounting groove 8 is located between two fixing grooves 10. The length of the bottom surface of the press-in part 41 is equal to the distance between the two first protrusions 112. In this embodiment, the fifth protrusion 421 includes a fifth inclined surface 422, and the acute angle formed between the fifth inclined surface 422 and the horizontal plane is 43°. The length of the fifth inclined surface 422 is greater than the length of the fourth inclined surface 322. When the fifth protrusion 421 is located in the fixing groove 10, the length of the fifth inclined surface 422 is greater than the distance between the end of the fifth inclined surface 422 away from the mounting groove 8 and the end of the corresponding silver sheet 6 bent away from the fixing groove 10. This ensures that the fifth inclined surface 422 can be completely pressed on the upper surface of the bent part when it is pressed against the bent part of the silver sheet 6, ensuring the firmness of the silver sheet 6 riveted in the deepening groove 9 and preventing the silver sheet 6 from falling off.

[0039] Example 2

[0040] This embodiment provides a riveting method for directly riveting a silver sheet 6 onto a copper strip 7 using the above-mentioned riveting mold, specifically including the following steps:

[0041] When the copper strip 7 is conveyed to the area directly below the first mold 1, the first punch part 11 of the first mold 1 punches out the mounting groove 8 on the copper strip 7; the copper strip 7 continues to be conveyed to the area directly below the fifth mold 5, and the mounting groove 8 is finely punched by the second punch part 51 of the fifth mold 5 to obtain a deepened groove 9; at this time, the silver strip is fed in from a direction perpendicular to the movement direction of the copper strip 7, and enters between the two second protrusions 211 of the two upper bending parts 21 and the third protrusion 221 of the lower bending part 22, so that the two ends of the silver strip in the width direction are bent; in the next stroke, the silver strip feeder feeds the bent silver strip into the platform 33 of the third mold 3, and the cutting part 31 first cuts the silver strip into the platform 33 of the third mold 3. The silver strip is cut into silver sheets 6 of the target specifications. Then, the cutting piece 31, assisted by a spring at its end, descends to feed the silver sheet 6 into the deepening groove 9. Next, two first upper mold pieces 32 press down, stamping two fixing grooves 10 on both sides of the deepening groove 9 containing the silver sheet 6. Finally, the copper strip is fed directly below the fourth mold 4, and the pressing piece 41 presses down, pressing the silver sheet 6 firmly into the deepening groove 9. Then, two second upper mold pieces 42 press down and enter the corresponding two fixing grooves 10, pressing the fifth inclined surface 422 of the fixing groove 10 against the upper surface of the bent portion of the silver sheet 6, further securing the silver sheet 6 in the deepening groove 9, thus completing the riveting of the silver sheet 6. This single step, completing the riveting of the silver sheet 6 during the terminal stamping process, improves terminal production efficiency.

[0042] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A riveting die for directly riveting silver sheets onto a strip during the stamping of terminals on the strip, characterized in that, The riveting mold sequentially includes a first mold, a second mold, a third mold, and a fourth mold located at corresponding workstations. The first mold is used to punch an installation groove on the strip. The second mold includes two upper bending parts and a lower bending part, with the bottom ends of the two upper bending parts matching the top ends of the lower bending parts. The second mold is used to bend the two ends of the silver sheet along its width. The third mold includes a cutting part and first upper mold parts located on both sides of the cutting part. The third mold is used to feed the bent silver sheet into the installation groove and punch fixing grooves at both ends of the installation groove. The fourth mold includes two second upper mold parts. The fourth mold is used to press the two fixing grooves, so that the fixing grooves press the bent portion of the silver sheet against the side of the mounting groove. The lower end of the first mold is provided with a first punching part. The first punching part includes a first part and first protrusions located at both ends of the first part. The height of the first part is less than the height of the first protrusion, and the length of the first part is less than the distance between the two first protrusions. A first inclined surface is provided between the side of the first part near the corresponding first protrusion and the side of the first protrusion near the first part. The first punching part is used to punch out the mounting groove on the strip. The two upper bending parts are provided correspondingly. The lower end of the upper bending part is provided with a second protrusion. The second protrusion includes a second inclined surface and the cross-section of the second protrusion is a right trapezoid. The upper end of the lower bending part is provided with a third protrusion. The third protrusion includes two third inclined surfaces, which are respectively close to the two second inclined surfaces. Two first upper mold parts are correspondingly arranged, and each first upper mold part has a fourth protrusion at its lower end. The cross-section of the fourth protrusion is trapezoidal, and the distance between the two fourth protrusions is greater than the distance between the two first protrusions. The length of the bottom surface of the cutting part is greater than or equal to the distance between the two first protrusions. The fourth mold includes a press-in part, and the length of the bottom surface of the press-in part is greater than or equal to the distance between the two first protrusions. Two second upper mold parts are correspondingly arranged, and each second upper mold part has a fifth protrusion at its lower end. The distance between the two fifth protrusions is greater than the distance between the two first protrusions.

2. The riveting die according to claim 1, characterized in that, The second inclined surface is parallel to the corresponding third inclined surface, and the distance between the two sides of the two second inclined surfaces near the upper end of the upper bending member is less than the length of the top surface of the third protrusion.

3. The riveting mold according to claim 2, characterized in that, The acute angle formed between the first inclined plane and the plane containing the bottom surface of the first protrusion, and the acute angle formed between the second inclined plane and the plane containing the bottom surface of the second protrusion, are both 44.9°-45.1°.

4. The riveting die according to claim 1, characterized in that, The device includes a fifth mold, the lower end of which is provided with a second punching part. The second punching part includes a second part and a sixth protrusion located at both ends of the second part. The height of the second part is less than the height of the sixth protrusion and greater than the height of the first part. The height of the sixth protrusion is greater than the height of the first protrusion. The length of the second part is less than the distance between the two sixth protrusions. The second punching part is used to deepen the mounting groove on the strip.

5. The riveting die according to claim 4, characterized in that, The fourth protrusion includes a fourth inclined surface, and the fifth protrusion includes a fifth inclined surface. The length of the fifth inclined surface is greater than the length of the fourth inclined surface. When the fifth protrusion is located in the fixing groove, the length of the fifth inclined surface is greater than the distance between the end of the fifth inclined surface away from the mounting groove and the end of the corresponding bent portion of the silver sheet away from the fixing groove.

6. A method for riveting using a riveting die as described in any one of claims 1-5, characterized in that, The process includes the following steps: using the first mold to punch out an installation groove on the strip, then using the second mold to bend both ends of the silver strip, using the third mold to cut the bent silver strip into a silver sheet and press it into the installation groove, and punching out a fixing groove on the strip, and finally using the fourth mold to press the silver sheet into the installation groove, and tilting the fixing groove near the installation groove towards the bent part of the silver sheet and pressing it onto the upper surface of the bent part to complete the silver sheet riveting.

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